Estimation of radiation doses from Cs-137 to frogs in a wetland ecosystem

Currently, there is no established methodology to estimate radiation doses to non-human biota. Therefore, in this study, various dose models were used to estimate radiation doses to moor frogs (Rana arvalis) in a wetland ecosystem contaminated with (CS)-C-137. External dose estimations were based on activity concentrations Of (CS)-C-137 in soil and water, considering changes in habitat over a life-cycle. Internal doses were calculated from the activity concentrations Of (CS)-C-137 measured in moor frogs. Depending on the dose model used, the results varied substantially. External dose rates ranged from 21 to 160 mGy/y, and internal dose rates varied between I and 14 mGy/y. Maximum total dose rates to frogs were below the expected safe level for terrestrial populations, but close to the suggested critical dose rate for amphibians. The results show that realistic assumptions in dose models are particularly important at high levels of contamination. (C) 2004 Elsevier Ltd. All rights reserved.